Fluid gear



May 31, 1932.

F. GRAUPNER FLUID GEAR Filed Jan. 18, 1928 I 221 812 01: E'ifz Gram aver Patented May 31, 1932 a UNITED s'r rss PATENT OFFICE FRITZ GRAUPNER, OF HANOVER, GERMANY FLUID GEAR Application filed January 18, 1928, Serial No. 247,707, and in Germany January 19, 1927.

My invention relates to fluid gears, for Fig. 2 is a section on the line 11-11 in instance to hydraulic gears for motor cars Fig. 1. and the like, of the type in which fluid such Referring now to the drawings, a is the as oil is forced through pipes. It is an object driving shaft and b is the driven shaft of of my invention to provide a gear of this the gear. Rotation is imparted to the driv- 55 type in which lossof power due to friction ing shaft by any suitable means, not shown, and complicated mechanismsas involved in for instance the engine of a motor car, to the gears having only partly mechanical gearing wheels of which the driven shaft b is conand a rotary container for the driving menected. 0 and d are turbine impellers, sedium, are avoided. cured to the ends of the driving and the 60 To this end, and with a view to simplifying driven shafts, respectively. e is a cylindrical the construction and improving the efiiciency casing open at both ends, in which the imas compared with the devices aforesaid, I pellers 0, d are rotatably mounted, and m have designed a gearing having a driving is a casing of larger diameter surrounding l5 and a driven part operatively connected by the casing e and provided with an oil supply 65 flowing liquid, for instance, a turbine impipe m, both casings being stationary and peller, a propeller or the like on the driving, connected by stays m", or other suitable and similar means on the driven shafts, remeans. The shafts a and b are inserted in spectively, these rotary parts being arranged the covers of the casing m through stufling no in a stationary casing and rotating in a meboxes at and b, respectively. 70

dium which will bereferred to as oil, but In the example illustrated, means are'proobviously may be any other suitable liquid vided for regulating the area at the open ends or fluid, and is drawn from the casing by the of the casing e and such means are shown as rotation of the driving shaft and returned dampers h, in the present instance six, at the to the casing after having imparted rotation discharge sideof the impeller 0, which are 75 to the driven shaft. fulcrumed in the casing 6 about radial shafts It is another object of my invention to pro- 2'. The dampers h, as will appear from Fig. Vide means for rendering the gear tempo- 2, are sector-shaped and their shafts i are rarily. inert so as to permit the oil to circufulcrumed in the casing e at their outer ends late when the driving shaft is rotating withand in a sleeve e.at their inner ends, the so out imparting rotation to the driven shaft. sleeve 6 surrounding the shaft a but not par- It is still another object of my invention taking in its rotation. The sleeve 6 may be to. provide means 'for varying. the area cast integral with. the casing c. It is underthrou hwhi'ch'the' oilcirculates and the angle: stood that instead of sectors as shown,

at which it strikes thevanes of the impeller dampers of any other suitable configuration 85 on the driving shaft so as to provide means may be provide Z is a sleeve adapted to for an additional regulation of thespeed of slide axially on the shaft a but held against the driven shaft and for exerting a braking rotation by means that will be described, Z is action on the driven shaft, and to this latter a spider having, in the present instance, three n I may' esign the eg l ng m n afOTearms, Z" are eyes on the sleeve Z one for each 0 said so as to retard or arrest the flow of oil ofthe dampers 71., lg are connecting rods exwith respect to the impeller on the driven tending from the eyes l"-to the ends of the shaft. dampers hand connected therewith by means In the drawings afli this sp c ati of ball-and-socket joints is or any other suitand mi g P r of a g r em ying "able means permitting rocking movement of on my inV i illustrated iagramm i y the dampers about their shafts 2' without inp by way of example. terfering with'the axial movement of the In the drawings, sleeve Z. 'n are stays extending in parallel Fig. 1 is an axial section of a gear accordto the axis of the gearing, 'nare stuflingboxes ing to my invention, and by which the stays are carried through the cover at the corresponding end of the casing m, 'and n is a sleeve similar to the sleeve Z and having a spider to which the stays n are connected. Any suitable means, not shown, may be provided for displacing the sleeve m axially on the shaft (1 and it will be understood that when such displacement occurs the dampers It will be rocked about their shafts z and the free area of the casing e at the discharge side of the impeller 0 will be varied, or the casing will be completely closed, as the case may be.

Similar means comprising dampers H on shafts I, sleeves L and N, stays N and connectin rods K, may be provided at the inlet side 0 the turbine d for regulating the free area of the casing at this end or for closing it altogether, as described.

f are valves in the barrel of the inner casing e which are forced from their seats by springs o and may be seated by any suitable means, for instance a cable 3) on a pulley g which cable is attached to the spindle f of the valve f. Any number of valves f may be provided, two valves being shown by way of example.

The operation of the gear-is as follows:

The gear is normally operated in the usual manner, with the impeller c on the driving shaft acting as the pump, and the impeller (13 on the driven shaft acting as the motor, with the liquid circulating from the right to the left in Fig. 1, i. e., from the impeller d to the impeller 0. The valves f are closed for the normal operation, and the dampers h and H are full open or partly closed as required for the desired ratio of ower transmission. The impeller 0 on the driving shaft a draws liquid from the outer casing m into the inner casing 0 through the dampers H and through the impeller d on the driven shaft 6, and returns the liquid to the casing through the dampers h. In this manner a continuous circulation of the liquid in the casings m and e is established and imparts rotation to the driven impeller or motor (1.

If it is desired to cut out the gear while the driving shaft a, with the impeller a, still rotates, the valves f are opened, and the circulation of the liquid between the casing m and e is short-circuited through the openings of the valves. The liquid now is drawn into the inner casing e through the valve openings and returned to the outer casing through the dampers h without influencing the impeller d on the driven shaft 6.

The gear may also act as a brake a ainst the rotation of the driven shaft 6. I it is desired to use the gear as a brake, the driving shaft a is arrested, the dampers h for the impeller 0, and the valves f are closed while the-dampers-H for the impeller d are opened. The impeller (i still rotates under the inertia actionof the vehicle or the like to which it is connected and now acts as apump which tends draw the liquid through the open dampers I H and force it into the inner casing e. By these means a strong resistance is opposed to the rotation of the impeller 03 on the driven shaft 6.

The air in the casing m may be utilized for generating an assisting starting torque. In order to store a supply of air under pressure for this purpose the impeller c on the driving shaft a is started with the dampers H closed or partly closed,drawing liquid from the casing 6 and delivering it to the casing m through the dampers h and generating a partial vacuum in front of the impeller d on the driven shaft 6. When the dampers H are now fully opened the liquid flows into the casing e under the considerable excess pressure of the air cushion and the suction of the partial vacuum in the casing e and imparts starting torque to the impeller 05 on the driven shaft, in addition to the torque exerted by the engine. In this manner, the static friction is overcome more readily than inexisting gears.

Instead of partly filling the casing, a separate air chamber may be provided in which a piston is reciprocating against resilient reaction, or the casing m may be made from resilient material, as rubber, so as to obtain a supply of energy, which may be utilized when starting the shaft 6.

When the impeller c is rotating while the dampers H are closed or partly closed so as to restrict the free area of the inner casing to a considerable extent, the quantity of liquid which the impeller 0 draws from the inner casing e is in excess of the quantity of liquid admitted by the dampers H and therefore pressure will build up in the casing m, compressing the air cushion in the impeller while its volume is reduced. Under these conditions, a zone of reduced pressure will form at the inner side of the impeller 03 while its outer side isunder the pressure of the liquid in the casing m this pressure being admitted through the gaps or leaks'between the dampers H. The pressure reacting on the impeller a is also increased but a very considerable starting torque will be available when the driven impeller d is thrown in.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described for obvious modifications will occur to a person skilled in the art.

I claim 1. A fluid gear comprising a driving and a driven shaft, an impeller on each shaft, an inner casing which is open at both ends and adapted to receive said impellers, an outer casing surrounding said inner casing and communicating therewith at said open ends, blades in each impeller which are rigidly connected with its respective shaft, means in said inner casing adapted to connect it to said outer casing, and means at one of the open ends of said inner casing for varying the free area of said open end. Y

2. A fluid gear comprising a driving and a driven shaft, an impeller on each shaft, an inner casing which is open at both ends and adapted to receive said impellers, an outer v casing surrounding said inner casing and communicatin therewith at said openends, blades in each lmpeller which are rigidly connected with its respective shaft, means in said inner casing adapted to connect it to said outer casing, and means at the open ends of said inner casing for varying the free area of said open ends.

3. A fluid gear comprising a driving and a driven shaft, an impeller on each shaft, an inner casing which is open at both ends and adapted to receive said impellers, an outer casing surrounding said inner casing and communicating therewith at said open ends,

blades in each impeller which are rigidly connected with its, respective shaft, and means at one of the open ends of said inner casing for varying the 'free area of said open end.

In testimony whereof I afiix niy si ature.

" FRITZ GRAUP ER. 

